Coaxlink Programmer's Guide
Euresys::EGrabber
int
main() {
try
{
EGenTL gentl;
MyGrabber grabber(gentl);
while
(
true
) {
}
}
catch
(
const
std::exception &e) {
std::cout <<
"error: "
<< e.what() << std::endl;
}
}
1. In
onNewBufferEvent
, create a temporary
ScopedBuffer
object
buf
. The
ScopedBuffer
constructor
takes two arguments:
• the grabber owning the buffer: since we are in a class derived from
EGrabber
, we simply pass
*this
;
• information about the buffer: this is provided in
data
.
2. Retrieve the timestamp of the buffer, which is defined as the time at which
the camera started to send data to
the frame grabber
.
3. As explained in the section about
event identification
,
new buffer
events are slightly different from the other kinds
of events: they are standard (as per GenTL), and don't have an associated
numid
.
As a consequence, the
NewBufferData
structure passed to
onNewBufferEvent
doesn't have a
numid
field. It
does, however, have a
timestamp
field indicating the time at which
the driver was notified that data transfer to
the buffer was complete
. This
event timestamp
is inevitably greater than the
buffer timestamp
retrieved in step 2.
4. We reach the end of the block where the local variable
buf
has been created. It gets out of scope and is destroyed:
the
ScopedBuffer
destructor is called. This causes the GenTL buffer contained in
buf
to be re-queued (given
back) to the data stream of the grabber.
Example of program output:
event timestamp: 77185931621 us, buffer timestamp: 77185919807 us
event timestamp: 77185951618 us, buffer timestamp: 77185939809 us
event timestamp: 77185971625 us, buffer timestamp: 77185959810 us
event timestamp: 77185991611 us, buffer timestamp: 77185979812 us
event timestamp: 77186011605 us, buffer timestamp: 77185999808 us
event timestamp: 77186031622 us, buffer timestamp: 77186019809 us
event timestamp: 77186051614 us, buffer timestamp: 77186039810 us
event timestamp: 77186071611 us, buffer timestamp: 77186059811 us
event timestamp: 77186091602 us, buffer timestamp: 77186079812 us
event timestamp: 77186111607 us, buffer timestamp: 77186099814 us
Relevant files
include/EGrabber.h
Main header. Includes all the other headers except
include/RGBConverter.h
. Defines
Euresys::EGrabber
,
Euresys::Buffer
,
Euresys::ScopedBuffer
include/EGrabberTypes.h
Defines data types related to
Euresys::EGrabber
include/EGenTL.h
Defines
Euresys::EGenTL
include/GenTL_v1_5.h
Standard GenTL header. Defines standard types, functions and constants
include/GenTL_v1_5_EuresysCustom.h
Defines Coaxlink-specific constants
include/RGBConverter.h
Defines
Euresys::RGBConverter
helper class
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